- Cook the sausage in a large pot of water for 20 minutes without piercing it. Meanwhile, in a bowl, mix the flour, yeast, and salt, then add the milk.
- Microwave the butter for 15 seconds and then add it to the mixture. Finally, add the egg and mix until you get a relatively soft dough.
- Line a loaf pan with parchment paper and pour the dough into it.
- Once cooked, remove the sausage from the water, put it on a plate, and remove its skin. Place the skin on the dough, turning it so that the dough covers it, and let it rest for 1 hour (away from drafts) or more if it is not warm enough in the room.
- Finally, once the brioche has doubled in volume, mix the remaining egg yolk with 1 tablespoon of water and brush it onto the brioche. Bake for 25 minutes at thermostat 8 (around 180°C).